1. Field of the Invention
The present invention relates to a system, method, and computer program product for comparing multiple versions of data item definitions.
2. Description of the Related Art
A database management system (DBMS) provides the capability to store, organize, modify, and extract information from one or more databases included in the DBMS. From a technical standpoint, DBMSs can differ widely. The terms relational, network, flat, and hierarchical all refer to the way a DBMS organizes information internally. The internal organization can affect how quickly and flexibly you can extract information.
Each database included in a DBMS includes a collection of information and other objects organized in such a way that computer software can select and retrieve desired pieces of data. Traditional databases are organized by fields, records, and files. A field is a single piece of information; a record is one complete set of fields; and a file is a collection of records. Most full-scale database systems are relational database systems. An important feature of relational systems is that a single database can be spread across several tables. This differs from flat-file databases, in which each database is self-contained in a single table. In fact, large relational database systems may include a large number of tables and other data objects, such as indexes, etc. In order for a data object to exist in a database, the data object and its characteristics must be defined by a data object definition. Typically, such data object definitions are stored as metadata of the data objects. Taken together, all the data object definitions define the design of the database. Typically, the data objects are organized by schemas, each of which includes at least a portion of the data object definitions.
As the design of a database system changes over time, it is important to database developers and administrators to be able to track the changes in the data object definitions of the database. The task is to compare two specified sets of database metadata object definitions, storing the comparison results, then to repeat the process at later points in time using the same selection criteria. Conventionally, all metadata object definitions that met the selection criteria are compared and all results stored each time the process is repeated. This is a costly and time-consuming process. A need arises for a technique by which data object definitions may be compared and the results stored that reduces the cost and time of the process.